1. Field of the Invention
This invention relates, in general, to hydraulic couplings, and specifically to hydraulic couplings used in undersea drilling and production applications. More particularly, the invention involves seals between male and the female coupling members in undersea hydraulic couplings.
2. Discussion of Prior Art
Subsea hydraulic couplings are old in the art. The couplings generally consist of a male member and a female member with seals to seal the junction between the male and female members. The female member generally has a cylindrical body with a relatively large diameter bore at one end and a relatively small diameter bore at the other. The small bore facilitates connections to hydraulic lines, while the large bore contains the seals and receives the male portion of the coupling. The male member includes a probe section insertable into the large bore of the female member. According to various embodiments of the device, the seals either abut the end, or face, of the male member or engage the male member about its outer circumference. Hydraulic fluid is then free to flow through the female and male portions of the coupling and seals prevent that flow from escaping about the joints of the coupling.
Optionally, a check valve may be installed in the female member and also in the male member. Each check valve is open when the coupling is made up; however, each check valve closes when the coupling is broken so as to prevent fluid from leaking out of the system of which the coupling is part.
Undersea hydraulic couplings may be connected or disconnected several times during their usage. For example, two or more undersea hydraulic coupling members may be attached to manifold plates or other structures that may be brought together using a remote operating vehicle. There may be some radial misalignment of the male and female coupling members during their assembly or connection. In some cases, the male coupling members may be securely attached to a manifold plate at a fixed subsea location, and the female coupling members then may be positioned onto the male coupling members. Because of misalignment between the male and female coupling members, the seals which may be held in the receiving chamber of the female coupling members may not completely engage all of the sealing surfaces of the male coupling members. Significant misalignment of the coupling members, and/or incomplete engagement of sealing surfaces, may cause or contribute to leakage of seawater into the couplings or loss of hydraulic fluid from the couplings.
U.S. Pat. No. 4,709,726 entitled Hydraulic Coupler With Floating Metal Seal relates to a floating retainer ring housed within the female coupling body. The floating retainer ring is metal or metallic.
An undersea hydraulic coupling with a floating seal is needed that will protect the surfaces of the coupling members from galling or other damage due to radial misalignment of the coupling members. Such a floating seal for an undersea hydraulic coupling is needed that will provide a seal with the female member and the male member during operation when there is possibility of radial movement inside the coupling. A reliable floating seal is needed between the male and female coupling members to withstand the high temperatures and high pressures in the subsea environment.